Bis(alpha,beta-dihaloalkyl) 1-acyloxyalkane phosphonates

ABSTRACT

THE NEW COMPOUNDS BIS(A,B-DIHALOALKYL) 1-ACYLOXYALKANE-PHOSPHONATES, AND PARTICULARLY BIS(2,3 DIHALOPROPYL) 1-ACYLOXYALKANEPHOSPHONATES ARE DISCLOSED WHICH HAVE BEEN FOUND TO BE EFFECTIVE FLAME RETARDANTS IN VARIOUS POLYMER COMPOSITIONS SUCH AS POLYMETHYL METHACRYLATE POLYSTYRENE.

A trile,polyacetal andepoxys. v I

The preferred compoun ds of the present invention are. bis(.2,3 dihaloalkyl) -1-acyloxyalkanephosphonates and iisfit u iii l 3,784,591 BKS((X,fiEEHAEOALKYL) LACYLOXYALKANE PHOSPHONATES Arthur ll), F, Toy, Stamford, Conn., and Eugene A,

Uhing, Ridgewood, N.J., assignors to Stautfer Chemical Company, New York, N.Y. No Drawing. Filed June 10, 1971, Ser. No, 151,953 int. Cl. C07f 9/40; (308i 45/58 Uh. tCll. 260-952 7 Claims ABSTRACT OF THE DISCLOSURE The new compounds, bis(a,B-dihaloalkyl) l-acyloxyalkane-phosphonates, and particularly bis(2,3 dihalopropyl) 1-acyloxyalkanephosphonates are disclosed which have been found to be effective flame retardants in various polymer compositions such as polymethyl methacrylate and polystyrene,

The present invention relates to new flame retardant compounds which can be effectively used as flame retard ant agents in numerous polymer systems and especially in polymethyl methacrylate and polystyrene.

THE INVENTION In accordance with the present invention there are provided the new flame retardant agents bis(u,;3-diha1oalkyl) 1-acyloxyalkanephosphonates which can be represented by the formula:

wherein R R R R R R and X are as depicted above, and R, and R independently represent C to C alkyl and hydrogen. R R R R and R are preferably hydrogen and the halogen radical is preferably derived from bromine. R and R are preferably alkyl groups having one carbon atom.

Polymers and processed polymers which-can be e'ifec tively flame retarded by these compounds can be illustrated by-polyurethanes, cellulosics and modified cellulosics (cel-= olefins, unsaturated polyester,'acrylics, including acryloniwill be used for illustration. The dihaloal kyl groups'jare based on a normal propyl group, e.g.', a-carbon chain of v 3, and which have halogens of eitherchlorine or bromine attached to both the 2 and 3 positions of the'p'ropyl group.

In addition to hydrogen, the prowl group can also be Substituted with other non-interfering organic groups. The

lulose acetate and rayon), vinyls including styrene, -po'ly-= 3,784,591 ttented Jan. 8, 1974 terminal or number 3 carbon can be substituted with one or more lower alkyl radicals having from 1 to 8 carbons illustrated by methyl, ethyl, propyl, isopropyl, butyl, iso butyl, pentyl, hexyl, heptyl, and octyl, as well as with the corresponding halogen derivatives (chlorine and bromine) thereof. These halo-substituted alkyls (haloalkyls) can be illustrated by chloromethyl, chloroethyl, chloropropyl, chlorobutyl, and the like, and the corresponding bromine derivatives. The number 1 and 2 carbons can be substituted with a C to C lower alkyl radical such as those given hereinbefore.

The 2,3 dihaloalkyl groups discussed above satisfy 2 of the phosphorus valences. The remaining valence of the phosphorus (after the oxygen) is satisfied by a 1-acy1oxy= alkane group of the formula:

wherein R represents alkyl groups of from 1 to 8 car= bons while R and R represent hydrogen or an alkyl group of C to C carbons as defined hereinbefore. R is, preferably, hydrogen or lower alkyl of l to 4 carbons and more preferably hydrogen. R and R are, preferably, lower alkyl of 1 to 4 carbons and more preferably methyl.

The preferred compounds of the present invention can be easily prepared by halogenating (chlorinating or brominating) diallyl 1-acyloxyalkanephosphonate. The meth-= ods for halogenating allylphosphates are well known in the prior art and can be illustrated by those set forth in US. Pat. 2,574,515.

The diallyl 1-acy1oxyalkanephosphonates can be easily prepared by reacting diallyl hydrogen phosphonate with an unsaturated ester such as vinyl acetate in the presence of a sodium alkoxidc. This reaction Will provide the diallyl 1-acyloxyalkanephosphonate compound which is the intermediate for preparing one of the lower members of the class of compounds claimed in the present invention.

Other methods for preparing the intermediates include the formation of an enol such as by the acid catalyzed addition of acetic acid and acetylene and also the sulfuric acid catalyzed reaction of ketone with acetone, followed by reacting the same with a dialkene phosphonate. The formation of higher ketones into their enol acetates is ac complished by the acetate exchange with the isopropenyl acetate in the presence of paratolucne sulfonic acid. Ketones which can be used are illustrated by methyl ethyl ketone, diethyl ketonc, acetophenone and the like.

Also, compounds within the broad scope of the in vention can be prepared by the reaction of dialltcne phon phonates of the formula:

0 Rr- G 11 :0 Its-11 09274? with aldehydes except formaldehyde) and ketones to yield oc OH phosphonates I Rt-capo n m onr ba on a Y v Ra anhydrides to give which can. be esterified with ketene vor carboxylic acid 'Halogenation of these compounds as outlined hereinbe I fore provides the compounds claimed in the present vention. t

chlorinated product is worked up using the same pro= cedure as shown in Example 1.

phonate and 160 grams of bromine in the procedure of Example 1.

(G) Bis(Z-methyl,2,3-dibromopropyl) 1 acetoxyeth= a EX AMPLE 3 anephosphonate using 138 grams of bis(2 methy1-2,3-= Pl'epal'atlml of P Py Pfofmoyleihane' 5 propylene) l-acetoxyethanephosphonate and 160 grams of phosphonates bromine in the procedure of Example 1.

a? (H) [(2,5 dichloropropyl)(2,3 dibromopropy1)] 1= acetoxyethanephosphonate using 124 grams of diall l 1= (mihlcfimommficmomwmo)? acetoxyethanephosphonate and 90 grams of bromine and In a 2 lTll'llllltef round bottom flask Fqulpped wlth a 10 35.5 grams of chlorine in the procedure of Example 1. mechanical stirrer, thermometer, dropping funnel and under which is positioned a solid carbon dioxide/acetone EXAMPLE 5 Cooling bath is Placed 31 grams mole) of diallyl The flame retardant additives of the present invention P P Q 361) grams moles) of Vinyl formate were combined with polymethyl methacrylate and tested and the mixture is cooled to 0 C. In the dropping funnel as follows: is placed a catalyst solution comprising a 10% solution of p l h l h l .s l f fi t d d sodium allylate dissolved in a 50/50 allyl alcohol/toluene polymathyl methacrylate (PMMA) are prepared by mixture. This catalyst solution was added portion-wise at a l i th proper amount f h fl retardant i 100 rate so that the reaction temperature did not rise above grams of h l methacrylate containing 0,04 gram of C The addition of Catalyst Was pp after the a polymerization catalyst (azobisisobutyronitrile). The thermic reaction ceased. The reaction mixture was allowed resulting solutions were poured into tubular molds and to warm to C. and another 1 to 2 milliliters of then heated to a temperature of between about M" C. catalyst was added cautiously. As no temperature rise and 90 C. The polymerization was allowed to proceed occurred, the reaction had gone to completed. The catalyst for a period of about 16 hours yielding solid polymer was then neutralized by adding 1 to 2 grams solid carbon 95 rods having a diameter of 10 mm. dioxide to the reaction mixture. This reaction mixture was The fire retardancy of the rods was then quantitatively brominated by adding 160 grams (1.0 mole) bromine evaluated by determining their Limiting Oxygen index using the same procedure showed in Example 1. The yield (LOI) by means of the procedure described in. Fenimore of product after washing was 260 grams or 94% of and Martin in the November 1.966 issue of Modern Platstheoretical for tics. In brief, this procedure directly relates flame retard 0 army to a mcfasurement of the minimum percentage con- 1 w t centration. 0 oxygen in an oxygcnmitro en mixture (LHBTLHBICHOMPcmm'moo(0m which permits the sample to burn; the LOI lJcing calcu- Nuclear magnetic resonance analysis confirmed the struc lated as follows: turea 0 EXAMPLE 4 tona fi x 100 Other compounds within the scope of the present in 2 J vention can 'be easily prepared by varying the phospho- Thus, a higher L0! is indicative 01. a higher dearth: of hate reactant in the foregong procedures as follows: flame retardancyv (A) Bis(2,3 dichloropropyl) 1 forrnoylethanephos- 40 The following table presents the results at? this ti litillfl phonate using 117 grams of diallyl 1-f0rmoy1ethanephoe= tion.

TABLE I Flame retardant; Percent. t,. l.l' i

Blank at out.) I) lit 2 (CH2BICHBIOH20)2P(O) OIHCI-I 0 0(0) 0 10 21; h 47 20 24.0 so

omnronnromonmo) .t 10 2o. 1 45 20 22.5 40

1 L.O.I.=Ltmitin Oxygen Index or percent oxygen at; which value the sample will burn for less than 3 minutes when ignited in the G51). Handle Tester. Values are :i .ii.

phonate and 71 grams of chlorine in the procedure of Ex= ample 3.

(B) Bis(3,4 dibromobutyl) 1-acetoxyethanephosphonate using 138 grams of bis(3,4-buty1ene) 1-acetoxyeth anephosphonate and 160 grams of bromine in the procedure in Example 1.

(C) Bis(3,4 butylene) 1 acetoxyethanephosphonate .i fililg' fi vgrains'of 'bis (3,4 buty1ene) phosphonate' andl ifi v grams o vinyl acetate in the-"procedure of Example 1.

1D). Bis 4,'fi'-dibromopeptyl) 1 acetoxyethanephos- I toxyethanephosphonate :andY IGD gramS of bromine in the proce'dur'e'ofExample'l'gf (E) 'YBis;(2,3'-dihromopropyl) i. acetoxypropanephosphonate u'sing- 131 grams oidiallyl1-acetoxypropanephos-' a er bromine'in the procedure of phonate and 160 v (P) Bis(2,3 -i vdill'iromopropyl) lacetoxybutanephos-- phonate-using 138, gra ns'of diallyl l-acetoxybutanephos- ,yhardness of: the polyincthyl niethacrylate is not decreased by'thense oi'the compounds of the prcsent'invcntioru These results show that the compounds of the present invention which contain 56% bromine and 55.4% phos' phorus are as effective ,as the lnominated triailyl'phos 'phate of the prior art which' contaius 68.7% bromine and EXAMPLE 6 v In manner similar to the preceding Example Ii, rods ot'rigid'polystyrenes were prepared by bulk polymerizing G grunts of styrene with 5 grams of divinyl benzene in wherein X and X independently represent halogen of W c he pl'fihent or UN gram of benzoyl PBLGXldG as catalyst chlorine or bmmme; R1, R2, R3 R5, and R7 and R23 nnd the esired amount of flame retardant. These rods d R d d l h d p C were tested for flan-re returdaney using the L.O.I. test given an 3 m epen em y Iepresent y roger} or to above with. the following results: 5 alkyl; R represents C; to C alkyl, and R and R repre TABLE H it 11 index as defined nbove. Hurdncss is again not affected by the n: invention 7 sent C to C alkylene radicals and C to C lower nlizyi {)0 substituted derivatives thereof.

(Cellulose itCBlElI UM- FIEMIIE retardant films of cellulose 2. Bis(2,?i-dihalopropyl) 1-acy1oxyalltanephosphonates nee/tuteare prepared by mixing the flame retardant C0111" of the formulas:

pounds oi linen-mics i. and 2 in a 20 weight percent solu tion of eelluloue acetate in rm 80/20 meiotic/methanol :tttl'lujt'ti ystent. The solution then cast into a 15 mil sheet and sir dried for about 1 hour followed by an oven 2 drying st 70" (M -80" C. for about 1 hour. The fire rew turriunt is used in such an amount that the final dry film trontnins uhoui of fire retardant based on the dry weight of the acetates Pure acetone can he used instead ot the acetone/methnnol solvent system.

thus Ill types of both synthetic and naturally derived polymers and eoinpounded polymers may be utilized in preparing the retardant compositions using the fire re- W'dam Milli/C18 0f the Pmficllt invention w wherein ii R it to; and it, indeuemlently irrirnumit All oi: the disclosed polymer systems are Well known hydmgcn C1 to Ca mm m e a t i E each has extensive utilities known those Skilled alkyl radical; ii and It, independently represent hydro m the art home oi the polymers are useful as Iibre an and (31 m C4x alkyl; and K in a halogen am mm- 1 formers whereas others are used for molding compositions from chlorgm or m m F F F to fmm Thc comllnsltlon do Bis (2,3- dilmlopropyl) l.--ut:ylmtyniltunnplms;:lmnut"a oi the invention can also be used equally as wellio these as recited in claim wherein said hnlo en radicals on; well ltnown utilities. The flame retardant additives can dam/ad from bmmimfl f; W with other g mmrd" Bis(2,fi -dihalimrouyl) l iltlylDliylllli'tlliifllit'lfil'liItlllitlttfl time the tlnrne retardants are incorporated in or on the as recited in claim wherein m Rh R2, Hm Hm mi m polymer as may be appropriate for the form of polymer 45 radicals am hydrogen:

usedadmlvcsi can w fe s f i ti. Bis(2fl-dihalopronyi) lneyloiiyallnimenhos honninu a. lSCtl tin ext usn'ni milling nnectton molding and the my jmimd in 3mm .wmmi mmwmmif, J MW f l P add! w l fq Sohltmns (2,3 dihronionropyl) IiiHi(Hiyllfi1l luphmfillililllitll)l which m films Also, addmvcs can be t. Bis(2,3--dil1alopropyl) imaylsllmnephouphon:1to; I;

midi? w spinning solutions" The additive-5 can also be "0 recited in claim wherein said phosphonntn it till ltlu X i i v I d 1 donned pulymcr shapes fibre bath (2,3 dichloro no iyl) l-neetoryethanepltosphonutet l lltltfl tlltu if; can he necorn plis hed by padding, dippi w 7, Bis(Z,Tlalihalonropyl) I--:icyhillnrmeygihosuhon1itun um i l WI i wln-opljlfw hqmd medium) d the t? recited in claim Wit" in mid phosphonutci in MAJ hi s the inn retardant add tives can be added to protective 3 dibmnwmmyllnmrmo mummphmpimnma t 7 l V an Lungs generally applied to the exterior of a structure such. {til a polymer based paint. These are given only as Mtfifmmmm 3 3 illustrative of the numerous utilities for the compositions k w l i of the iii-Union: V q hilifillillun' IATIMJ [Amid] It 0 H [M invention is defined in the claims which follow; 3,12h10o 12/1964 liturgy mitt-hm is elnime W n H 3 e V Uiiihit trill .ti itdiu t iriruuuailt iii no tor: all'aneaho shonates a y. y W jai i y fly 1 Filmer et all: "Mmmieul in ens," willa M; Mitt it (1966),

X X L ---Iii---- -In .fiti l'l'ful i EFF. filifi li'ii i i'ii'uitiy iiZJtiittlltitlli' n5 '""E or :ittit i 106--i" i i; ilfitl dfiitfi it, ill? t-t It ii 

